add proper pagination

daeddy · daeddy · commit 6a110f9ef5b0 · 2025-02-22T16:03:26.000+09:00
diff --git a/back_end/src/handlers/pagination.go b/back_end/src/handlers/pagination.go
@@ -0,0 +1,34 @@
+package handlers
+
+const (
+	DefaultLimit = 10
+	DefaultPage  = 1
+)
+
+// Based on https://dev.to/rafaelgfirmino/pagination-using-gorm-scopes-3k5f
+
+type Pagination struct {
+	Limit      int         `json:"limit,omitempty" form:"limit"`
+	Page       int         `json:"page,omitempty" form:"page"`
+	TotalRows  int64       `json:"total_rows"`
+	TotalPages int         `json:"total_pages"`
+	Rows       interface{} `json:"rows"`
+}
+
+func (p *Pagination) GetOffset() int {
+	return (p.GetPage() - 1) * p.GetLimit()
+}
+
+func (p *Pagination) GetLimit() int {
+	if p.Limit == 0 {
+		p.Limit = DefaultLimit
+	}
+	return p.Limit
+}
+
+func (p *Pagination) GetPage() int {
+	if p.Page == 0 {
+		p.Page = DefaultPage
+	}
+	return p.Page
+}
diff --git a/back_end/src/handlers/taskHandler.go b/back_end/src/handlers/taskHandler.go
@@ -2,8 +2,6 @@ package handlers
 
 import (
 	"net/http"
-	"strconv"
-	"time"
 
 	"back_end/src/models"
 
@@ -21,7 +19,7 @@ func (h *TaskHandler) CreateTask(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
 	}
-	task.CreateDate = time.Now()
+
 	if err := h.DB.Create(&task).Error; err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
@@ -30,16 +28,31 @@ func (h *TaskHandler) CreateTask(c *gin.Context) {
 }
 
 func (h *TaskHandler) GetTasks(c *gin.Context) {
+	var pagination Pagination
+	if err := c.ShouldBindQuery(&pagination); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
 	var tasks []models.Task
-	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
-	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "10"))
-	offset := (page - 1) * limit
+	offset := pagination.GetOffset()
+	limit := pagination.GetLimit()
 
 	if err := h.DB.Offset(offset).Limit(limit).Find(&tasks).Error; err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
-	c.JSON(http.StatusOK, tasks)
+
+	// Calculate total rows and pages
+	var totalRows int64
+	h.DB.Model(&models.Task{}).Count(&totalRows)
+	totalPages := int((totalRows + int64(limit) - 1) / int64(limit))
+
+	pagination.TotalRows = totalRows
+	pagination.TotalPages = totalPages
+	pagination.Rows = tasks
+
+	c.JSON(http.StatusOK, pagination)
 }
 
 func (h *TaskHandler) GetTask(c *gin.Context) {
diff --git a/back_end/src/models/task.go b/back_end/src/models/task.go
@@ -11,6 +11,5 @@ type Task struct {
 	Name        string    `json:"name"`
 	Description string    `json:"description"`
 	DueDate     time.Time `json:"due_date"`
-	CreateDate  time.Time `json:"create_date"`
-	Status      string    `json:"status"`
+	Status      string    `json:"status" gorm:"-"`
 }

Original file line number	Diff line number	Diff line change
`@@ -11,6 +11,5 @@ type Task struct {`
`11`	`11`	Name string `json:"name"`
`12`	`12`	Description string `json:"description"`
`13`	`13`	DueDate time.Time `json:"due_date"`
`14`		- CreateDate time.Time `json:"create_date"`
`15`		- Status string `json:"status"`
	`14`	+ Status string `json:"status" gorm:"-"`
`16`	`15`	`}`